D-amino acid aminotransferase1 regulates grain chalkiness in rice by modulating endoplasmic reticulum stress response

H Hui Dong (School of Chemistry and Chemical Engineering) J Jie Lei (Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology) Y Yunlu Tian (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, National Observation and Research Station of Rice Germplasm Resources, Sanya Institute of Nanjing Agricultural University, Jiangsu Engineering Research Center for Plant Genome Editing, Nanjing Agricultural University) J Juan Liu H Hang Yang X Xiaokang Jiang (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) R Rushuang Zhang (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) Y Yu Zhang (Xiangya Hospital, Central South University Changsha China) R Rongbo Chen (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) Y Yiqun Bao (College of Life Sciences, Nanjing Agricultural University) F Feng Liu Y Yulong Ren (State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences) Y Yaping Lu (College of Life Sciences, Nanjing Agricultural University) X Xi Liu (School of Chemistry and Chemical Engineering) S Shijia Liu (Peptide Biology Laboratory, The Salk Institute for Biological Studies) X Xue Yang E Erchao Duan (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) X Xuan Teng (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) Y Yunlong Wang (State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment) C Chuanwei Gu (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) Y Yipeng Zhang (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) X Xiaoli Chen Y Yunpeng Zhang (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) H Hongyi Xu R Rui Sha (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University) X Xia Xu R Ruomeng Li (Department of Chemistry, Center for Bioanalytical Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology) G Gongyu Li (Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry) Y Yihua Wang J Jianmin Wan (State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, National Observation and Research Station of Rice Germplasm Resources, Sanya Institute of Nanjing Agricultural University, Jiangsu Engineering Research Center for Plant Genome Editing, Nanjing Agricultural University)

Abstract

D-amino acids are key components of the bacterial cell wall and play important roles in neural communication and inflammatory responses in animals. However, knowledge about D-amino acid metabolism and physiological functions in plants is limited. Here, we isolated and characterized a rice D-amino acid aminotransferase1 , OsDAAT1 , which maternally regulates rice grain chalkiness through map-based cloning and a subsequent complementation test. We found that OsDAAT1 is highly expressed in the vascular tissue of rice nodes and is capable of interconverting different D-amino acids in vitro. Mutation of OsDAAT1 results in elevated D-alanine levels in stems, nodes, and developing grains. The disruption of D-amino acid metabolism subsequently leads to significantly altered peptide/protein isomerization, including some key enzymes involved in starch and protein biosynthesis. These changes trigger severe endoplasmic reticulum stress and ultimately leads to chalky grains. Furthermore, we identified OsDAAT1 Hap1 as a low-chalkiness haplotype, and historical frequency analysis suggests that OsDAAT1 may have undergone selection during rice domestication. Overall, our findings uncover a previously unrecognized role in D-amino acid metabolism in plants and facilitate the practical use of OsDAAT1 in grain appearance quality improvement in rice.

Article Details

Volume / Issue Vol. 123, Issue 10
Published March 10, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (30)

H

Hui Dong

School of Chemistry and Chemical Engineering

J

Jie Lei

Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology

Y

Yunlu Tian

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, National Observation and Research Station of Rice Germplasm Resources, Sanya Institute of Nanjing Agricultural University, Jiangsu Engineering Research Center for Plant Genome Editing, Nanjing Agricultural University

J

Juan Liu

H

Hang Yang

X

Xiaokang Jiang

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

R

Rushuang Zhang

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

Y

Yu Zhang

Xiangya Hospital, Central South University Changsha China

R

Rongbo Chen

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

Y

Yiqun Bao

College of Life Sciences, Nanjing Agricultural University

F

Feng Liu

Y

Yulong Ren

State Key Laboratory of Crop Gene Resources and Breeding, National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences

Y

Yaping Lu

College of Life Sciences, Nanjing Agricultural University

X

Xi Liu

School of Chemistry and Chemical Engineering

S

Shijia Liu

Peptide Biology Laboratory, The Salk Institute for Biological Studies

X

Xue Yang

E

Erchao Duan

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

X

Xuan Teng

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

Y

Yunlong Wang

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment

C

Chuanwei Gu

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

Y

Yipeng Zhang

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

X

Xiaoli Chen

Y

Yunpeng Zhang

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

H

Hongyi Xu

R

Rui Sha

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, Zhongshan Biological Breeding Laboratory, Jiangsu Nanjing Rice Germplasm Resources National Field Observation and Research Station, Nanjing Agricultural University

X

Xia Xu

R

Ruomeng Li

Department of Chemistry, Center for Bioanalytical Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology

G

Gongyu Li

Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Science, Frontiers Science Center for New Organic Matter, College of Chemistry

Y

Yihua Wang

J

Jianmin Wan

State Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, National Observation and Research Station of Rice Germplasm Resources, Sanya Institute of Nanjing Agricultural University, Jiangsu Engineering Research Center for Plant Genome Editing, Nanjing Agricultural University